The principle aim of this career development plan is to provide the candidate with the training, support, and resources required to develop as in independent investigator in the field of neuropsychiatric research. The candidate's long-term goals are to advance the knowledge of the developmental neuropathology of bipolar disorder by establishing a multidisciplinary research program that combines clinical (psychosocial and pharmacologic), developmental, and neuroimaging methods. The candidate's short-term goals for the duration of this award are to develop expertise in the following areas: (1) methods, design and analysis of multimodal (structural and functional) MRI studies; (2) cognitive neuroscience and neuropsychology; (3) research on the normal and abnormal developmental of brain networks. These training goals will be met through a combined program of coursework, consultation with established research scientists in these fields, and completion of a research study at the University of Utah's Brain Institute. The design and hypotheses of the proposed study were based on a growing body of work (including the candidate's prior research) indicating that bipolar disorder is a developmental brain disorder whose pathophysiology is associated with aberrant maturation of brain networks. Complicating the early-onset bipolar literature is the inclusion of high rates of youths with comorbid ADHD making it difficult to determine whether the neuroanatomical correlates are associated with bipolar disorder, attention-deficit/hyperactivity disorder (ADHD) or both disorders. Accordingly, the research plan proposes to evaluate a specific resting-state network (the default mode network) in 2 groups of adolescence: bipolar disorder without comorbid attention-deficit/hyperactivity disorder (ADHD) and healthy youths. This study will utilize a multimodal approach incorporating 2 types of neuroimaging techniques shown to measure brain connectivity: functional MRI and diffusion tensor imaging. The first major aim of this study is to examine the structural and functional connectivity of the default mode network in healthy adolescents. The second major aim of this study is to determine if these two complementary neuroimaging techniques can detect distinct differences in the default mode network between psychiatrically healthy youths and those with bipolar disorder without comorbid ADHD. This information will provide the foundation for future longitudinal investigations regarding the normal and abnormal development of this network.